The inventive concepts described herein relate to a semiconductor memory device, and more particularly, relate to a nonvolatile memory device and a sub-block managing method thereof.
Semiconductor memory devices may be volatile or nonvolatile. The volatile semiconductor memory devices perform read and write operations at a high speed, while contents stored therein may be lost at power-off. The nonvolatile semiconductor memory devices may retain contents stored therein even at power-off. The nonvolatile semiconductor memory devices may be used to store contents that must be retained regardless of whether they are powered.
A flash memory device is a typical nonvolatile semiconductor memory device. A flash memory device may be used as a voice and image data storing medium for information appliances, such as a computer, a cellular phone, a PDA, a digital camera, a camcorder, a voice recorder, an MP3 player, a handheld PC, a game machine, a facsimile, a scanner, a printer, and the like.
Recently, semiconductor memory devices having memory cells that are stacked in three dimensions have been researched to improve integrity of the semiconductor memory devices. However, increases in storage capacity may cause various problems due to mismatch with conventional memory management policies, for example.